Method of manufacturing and treating composite aluminium oxids.



UNITED STATES PATENT OFFICE. i v MAX BUCHNER, OF MANNHEIM-WALDHOF, GERMANY. umor) or mnur'ac'rnnnro AND mirarme courosrrn Ammm'run oxms.

site aluminium oxids has hitherto been e acted by smelting mixtures of aluminium oxid 'and' other oxids. The applicant has made the surprising observation that the manufacture of these compounds, hitherto only obtainable by smeltmg, can be also accomplished by heati molten aluminium oxid with-compounds the metals or metalloids loids. The process is carried out as follows, that is to say, ground molten artificial or natural aluminium oxid mixed with round oxygen compounds with or without t eaddition of binding materials is molded to the desired shape andthen heated. The reaction takes place at temperatures which are considerably elow the fus' int. The degree of fineness of the ingre lents can be varied within wide limits. Also the proportions of molten" aluminium oxid and oxygen compounds can -be largely varied. It is thus possible to obtain complpunds of very different properties and capa le of a variety of applications. Furthermore, further oxygen compounds can be introduced. into compounds of aluminium oxid and oxygen compounds obtained by smelting b .mere admixture and heating. If, for examp e, amixture of m nesium oxid and aluminium oxid is in question chromium oxid or copper oxid can be added thereto.

The following examples illustrate the mode of carrying out the invention 1 Iron magnesium silicon aluminium 8.45 parts by weight of Fe,0,, grain 120, 40.00 parts by weight of 0 grain 0, 10.71 parts by weight of Si rain 0, 81.00 parts by weight of fuse aluminium oxid sin 0. These ingredients are mixed together,

Specification of Letters Patent.

Application 111011 lay 10, 1807. I Serial No. 372,911.

or metals and metal Patented larch 31, 1908.

- made into a paste with water, formed into bricks and then burned.

Chromium-iron-r'ridgnesiumluminium 0 .95 parts by weight of fused chromium oxid-aluminium oxid grain 120, 8.2 parts by weight of iron 0x1d, grain 120, 40.00 parts by weight of magneslum oxid,

grain 0.

These ingredients are treated as ample 1, molded and burned. 3. Copper-aluminium oxid..

79 parts by weight copper oxid, grain 0,

under Ex- 102 parts by weight fused alumimum oxid gra1n-120, 15 parts by weight kaolin. Y

These ingredients are mixed, worked into apaste wit water, formed into bricks and burned.

. By rain 0 in the above examples. is meant t at the material is reduced to a condition of dust or powder. Grain 120 is used to indicate that'the material is reduced to a condition in which the particles are of the size of fine sand. Grain 60 .indicates' an intermediate condition .of fineness betweengrain 0 and grain 120. a

The new process has the advantage that it is not necessary as hitherto to fuse thevarious components of any aluminium com ound to be obtained but only to bring one 0 them into the molten condit1on. By this means it will be possible when, for example, an electric current is employed for fusing, to replace the'costlyelectrical energy by the cheaper heat of chemical combinations and, at the same time to avoid by-reactions which are set up by the chemical action between easily reducible oxids and carbon electrodes. For example, iron-copper-chromium oxid cannot be treated without difiiculty by reason of the fact that it is. easily reduced and of its high fluidity. At the same time the new process ermitsof the manufacture of compounds iiom their components and burning the articles formed therefrom (see Example 3) in this way the separate smelting hitherto considered as absolutely necessary is avoided and utensils are obtained which are of equal technical value.

The shrinkage under burning and the binding capacity of ceramic masses prepared by the above "described process sometimes require reduction. In this case the oxid mixture is first burned and able extent and employed as chamotte. The

, following example lllustrates this 5 4.40 parts by weight of magnesia, grain 0.

102-parts by weight of fused aluminium oxid, grain 0." 284 parts by weight of burning 1 part by weight of magne- 10 sia and 2.5 parts by-weight of fused chromium oxid aluminium oxid,

ain 60, 20 parts by weight of kaolin, 10 arts by weight of silicic acid.

It be obvious that oxid mixtures used as chamotte also contain ceramic binding substances.

Having now particularly described and ascertained the nature of my said invention ound to a suit-1 the product by and in what manner the same is to be per- 20' formed, I declare that what I claim is:

A process for the manufacture of combinations of fused aluminium oxid and 0 gen compounds of the metals or metalloi or 'metals and metalloids characterized (1) by 25 H. W. HARRIS, JAs. H. LEUTE. 

